hello!I purified antibodies by affinity chromatography and my problem is that the amount in fine is not that great and after some time stored at 4°C or even -20°C it is not working that well in blot (I have to increase the concentration) even though it's working fine in IF!

all suggestions, commentaries, help, withcraft will be welcomed!!

-SMH-

I, too, found decreasing activities of antibodies when stored at 4 or -20°C for some time. one possibility is to add some sodium azide to conserve the AB, or, the method better suited for me, store small (1-5 usage doses) aliquots at -80°C, thaw only once and use up the antibody quickly...